改良式地下渗滤系统处理农村生活污水工艺研究

发布时间：2018-07-21 12:26

【摘要】：近年来,我国农村水污染和水资源短缺现象十分严重。然而,大部分农村地区缺少污水收集管网和净化设施,生活污水基本上未经过处理就直接排放,使江河湖泊等水体污染严重,甚至威胁到村民的饮用水水质安全。因此,农村生活污水亟需治理。地下渗滤系统,作为一种典型的分散式小型污水处理设施,是目前处理农村生活污水的最佳手段之一。但是传统的地下渗滤系统由于结构及运行原因,往往不能同时形成很好的好氧和厌氧环境以供微生物进行硝化和反硝化反应,故对总氮净化效果不理想。因此,本研究以脱氮性能的改善为基本的立足点,采用对比实验,分别研究了不同的基质装填、组合方式和不同的运行条件对污染物去除效果的影响,从而提出系统结构改良和运行工艺优化的方案；同时,对系统内部的微生物数量、活性以及代谢多样性等指标进行了测定,并分析其与水质指标净化的相关性,为系统脱氮性能的改善提供理论支持。本研究主要成果如下：(1)基质装填和组合的方式会影响系统的净化效果。其中,完全混合装填和沸石、活性炭、粘土陶粒体积比为8：3：3的组合方式对污染物的净化效果要分别好于分层装填和沸石、活性炭、粘土陶粒体积比为3：2：2的组合方式,即各个系统对污染物的净化效果依次为：系统4系统3(或系统2)系统2(或系统3)系统1。系统4对CODCr、NH4+-N和TN的去除率分别为79.5%、88.7%和87.7%,比系统1要分别高出7.0%、4.5%和3.7%。(2)系统的处理效果随水力负荷的降低和干湿比的增加而升高。水力负荷为0.1～0.3m3/(m2·d)时,系统对污染物的净化效果差别很小；当其提高到0.4m3/(m2·d)时,对CODCr、NH4+-N和TN的去除率较0.1m3/(m2·d)时均有15%-20%的下降。间歇进水时对污染物去除效果要明显好于连续进水,干湿比为3：1时,系统对CODCr和TN的去除率比连续进水时分别提高10%和20%左右,对NH4+-N的去除影响较小。所以水力负荷为0.1m3/(m2·d),干湿比为3：1是系统最佳的运行状态,但综合考虑净化效果和处理能力,实际工程中可以选用0.3m3/(m2·d)的水力负荷和2：1的干湿比。(3)微生物数量和微生物活性与地下渗滤系统的净化能力具有极显著的正相关关系,即随着微生物数量的增多和活性的提高,系统对污染物的去除率也会增加；但微生物代谢活性及代谢多样性与系统处理效果没有相关性,不会影响系统对污染物的去除。
[Abstract]:In recent years, China's rural water pollution and water shortage is very serious. However, most rural areas lack sewage collection networks and purification facilities, and domestic sewage is discharged directly without treatment, which causes serious pollution of rivers and lakes, and even threatens the safety of drinking water quality of villagers. Therefore, rural domestic sewage is in urgent need of treatment. The underground leachate system, as a typical decentralized sewage treatment facility, is one of the best ways to treat rural domestic sewage. However, due to the structure and operation of the traditional underground leachate system, it is often unable to form a good aerobic and anaerobic environment at the same time for the nitrification and denitrification of microorganisms, so the purification effect of total nitrogen is not ideal. Therefore, with the improvement of denitrification performance as the basic foothold, the effects of different substrate loading, combination methods and different operating conditions on the removal efficiency of pollutants were studied by comparative experiments. At the same time, the quantity, activity and metabolic diversity of microorganism in the system were determined, and the correlation between the improvement of system structure and purification of water quality index was analyzed. It provides theoretical support for improving the denitrification performance of the system. The main results of this study are as follows: (1) the way of matrix filling and combination will affect the purification effect of the system. Among them, the purifying effect of complete mixed loading and zeolite, activated carbon, clay ceramsite volume ratio of 8:3:3 to pollutants is better than that of layered loading and zeolite, activated carbon, When the volume ratio of clay to clay is 3:2:2, the decontamination effect of each system is as follows: system 4, system 3 (or system 2), system 2 (or system 3) system 1. The removal rates of NH4-N and TN in system 4 were 79.5% and 87.7%, respectively, which were higher than those in system 1 by 7.5% and 3.775% respectively. (2) the treatment efficiency of the system increased with the decrease of hydraulic load and the increase of dry-wet ratio. When hydraulic load is 0.1~0.3m3/ (M2d), the effect of purifying pollutants by the system is very small, and the removal efficiency of NH4-N and TN of CODCrN is 15% -20% lower than that of 0.1m3/ (m2 d) when it is raised to 0.4m3/ (m2 d). The removal efficiency of COD _ (Cr) and TN was increased by about 10% and 20% respectively when the dry and wet ratio was 3:1, and the removal rate of NH _ 4-N was little. Therefore, the hydraulic load of 0.1m3/ (m ~ 2 d), dry-wet ratio is 3:1) is the best running state of the system, but the purification effect and treatment ability are considered synthetically. In practical engineering, the hydraulic load of 0.3m3/ (M2d) and dry-wet ratio of 2:1 can be selected. (3) there is a very significant positive correlation between the quantity and activity of microorganism and the purification ability of underground leachate system, that is, with the increase of the number and activity of microorganism, The removal rate of pollutants was also increased, but there was no correlation between microbial metabolic activity and metabolic diversity, which would not affect the removal of pollutants by the system.
【学位授予单位】：中国海洋大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X799.3

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